The rule says: place a colon/comma in front of direct speech, but not always. For example: So I would not punctuate a sentence like: But when the sentence becomes longer, it feels a little bit more uncomfortable. What do you think?
THese look fine to me because the sentence flows into the quoted material. A comma would break up that flow. You might do without the quotation marks in your first and second sentences, though that depends on the context. For instance, she said she was smart and pretty means the sayer says she's smart and pretty. The second one says he literally said the words "smart and pretty."
I personally find it tiresome/distracting to read sentences hyphyned like you did. I would prefer it without because then it would take the stress of the meanings. He said she was smart and pretty. He emailed a brief hello. However propably needs rewording again I would say as to avoid the hyphens again. Like This: He emailed her to say he would see her later. then He emailed a brief note to ask her what she wanted for lunch.
Get rid of the quotation marks. You're directly quoting him, yes, but it's not dialogue, so it's a little bit confusing, not to mention unnecessary. Same deal almost. You can get away with that, or you can write: He emailed her a brief, "Hello." So, again, you can treat it as though you're paraphrasing it, or you treat it as dialogue. Don't go halfway between. If you're treating it as dialogue as you are here, you need the comma. He emailed her a brief, "See you later." He emailed her a brief, "What would you like to have for lunch?" On another note, I really hope you're not being that repetitive in the actual prose. Change it up a bit. "See you later," the e-mail said. She opened the message and read, "What would you like to have for lunch?" Hope that helps. ... How is it that you can spell 'hyphen' incorrectly in one instance and correctly in another instance in the same post? Also, what hyphens? There aren't any hyphens at all. Also, there's nothing wrong with the original wording. It just needs to be treated as dialogue, and it's not really up to you to change the basic structure of his sentence.